Process for the production of benzotriazole derivatives



United States Patent 3,505,318 PROCESS FOR THE PRODUCTION OF BENZOTRIAZOLE DERIVATIVES Carl-Wolfgang Schellhammer, Opladen, and Wolf-Dieter Wirth, Cologne-Stammheim, Germany, assignors to Farbenfabriken Bayer Aktiengsellschaft, Leverkusen, Germany, a corporation of Germany No Drawing. Filed Mar. 29, 19 68, Ser. No. 717,397 Claims priority, applicatison Germany, Apr. 1, 1967,

Int. Cl. C07d 57/02, 55/04; C09b 23/14 US. Cl. 260240 2 Claims ABSTRACT OF THE DISCLOSURE Process for the production of novel benzotriazole derivatives, characterized in that a benzotriazole-(2)-acetic acid of the general formula in which x stands for 1, 2 or 3, and R means hydrogen, alkyl, alkoxy, acetylamino, dialkyla-mino, whereby the alkyl groups, together with the nitrogen atom, may be components of a heterocyclic ring which may also contain as further hetero atom oxygen, sulphur or nitrogen, halogen, CN, COOH, SO H or SO -a1kyl,

is reacted with at least the stoichiometrically required amount of an optionally substituted benzaldehyde of the formula in which y stands for 1, 2, or 3, and R may be identical with or difierent from R and where one of the radicals R may also denote an aldehyde group,

in the presence of piperidine, within a temperature range of about 120 to about 200 C., and the water formed in the reaction is continuously removed if desired.

The invention further comprises the novel benzotriazole derivatives formed by the noted process and having the general formula 2) y \HHH in which x and y stand for 1, 2, or 3, and wherein R has the same meaning as that above, R may be identical with or different from R and may also denote, if y is equal to 1, the radical 3,505,318 Patented Apr. 7, 1970 "Ice It has been found that novel benzotriazole derivatives are obtained when a benzotriazole-(2)-acetic acid of the general formula in which x stands for 1, 2 or 3, and wherein R denotes hydrogen, alkyl, alkoxy, N0 acetylamino, dialkylamino, whereby the alkyl groups, together with the nitrogen atom may also be components of a heterocyclic ring which may also contain as a further hetero atom oxygen, sulphur or nitrogen, halogen, CN, COOH, SO H or SO -alkyl,

are reacted with at least the stoichiometrically required amount of an optionally substituted benzaldehyde of the formula in which y stands for 1, 2 or 3, and R may be identical with or different from R and wherein one of the radicals R may also mean, in addition, an aldehyde group,

\ piperidine N-CHg-OOOH 0110 m 2 I The starting compounds to be used for the process according to the invention are known or they can be obtained according to known processes. Examples of benzotriazole-(2)-acetic acid derivatives are the following:

4-nitro-benzotriazole-(2)-acetic acid 4-methyl-benzotriazole-(2)-acetie acid 4,7-dimethyl-benzotriazole-(2)-acetic acid 4,5,7-trimethyl-benzotriazole-(2)-acetic acid 4-methoxy-benzotriazole-(2) -acetic acid S-methoxy-benzotriazole-(2)-acetic acid S-acetylamino-benzotriazole-(2)-acetic acid 4,7-dichloro-benzotriazole-(2)-acetic acid S-bromo-benzotriazole-(Z) -aoetic acid S-methylsulphonyl-benzotriazole-(2)-acetic acid 5-cyano-benzotriazole-(2)-acetic acid benzotriazole-(2)-acetic acid-S-suphonic acid The benzaldehydes which are used and may be substituted are known from the literature.

The process is carried out within a temperature range of about 120 about 200 C., preferably at 140-180 C. The piperidine required for the reaction can be used in off with suction. The crude, moist material is dissolved hot in a mixture of 1220 cc. concentrated hydrochloric acid and 775 cc. water, and the solution is slowly cooled. There separate 38 go S-methyl-benzotriazole-(2.) -acetic acid of MP. l92-l93 C.

catalytic amounts as well as in molar amounts referred to 5 the carboxylic acid used. EXA MPLE 3 The process can be carried out in the absence as well 300 5-mtfo'benlotflalole-(2)acetic acid, 145 gas in the presence of organic diluents boiling above about berflaldqhyde and 110 Piperldine are heatfid at w 120 C, B way f l thre may b mentioned while stirring, and the water formed in the reaction is as diluents 1,2-dich1orobenzene or 1,2,4-trichlorobenzene. dlstllled The melt is Poured int) 3 litres methanol In general, it is expedient to continuously remove during After coolll'lg, the Separated Yellow Crystals are filtered the reaction the water liberated in the course of the re- Off with suctlon f redissolved from glycol-monomethyl ti ether acetate. 5-mtro-2-styryl-benzotriazole of M.P. 168

Working up of the reaction mixtures to isolate the Q15 Obtamedbenzotriazole derivatives is carried out in known manner. In an analogous manner there are Obtained:

The novel 2-styryl-benzotriazoles obtainable according N to the process according to the invention are valuable zN intermediates for the production of dyestuffs. Some of R these compounds have a blue fluorescence. 2O

EXAMPLE 1 N 1 R 01 r tal M. 17.7 g. benzotr1azole-(2)-acet1c acid, 11 g. benzaldehyde 0 our 0 crys s P C and 5 cc. piperidine are heated to 160-17 0 C., while stir- :Sg 523 ring. The water formed in the reaction is distilled otf. CH After one hour, the contents of the flask are poured on a to ice-Water, the mixture is rendered acid to Congo red Red 170-176 with concentrated hydrochloric acid and the precipitated on, material is filtered oil. There is obtained 2-styryl-benzotri- Yellow 209 =azole 1n the form of pale yellowish-greenlsh crystals which 1 melt at 80-82 C. after redissolution from N,N-dimethyl- The 5-nitro-benzotriazole-(2)-acetic acid was obtained formamide/water. as follows: 551 g. 5-nitro-benzotriazole, 410 g. chloro- Solutions of the compound in N,N-dimethy1formamide acetic acid sodium salt, 5 litres water and 138 g. sodium or ethyl acetate exhibit in daylight an intense, violethydroxide are heated at boiling temperature for 16 hours, blue fluorescence. while stirring. The reaction mixture is then rendered acid The following compounds are obtained in an analogous to Congo, the separated material is filtered off with sucmanner: tion and redissolved from 20% hydrochloric acid. There NCH=OHX N Y Colour of X Y crystals M.P. 0. Fluorescence 120-125 Blue. 116-120 Blue-green. 260-265 215-217 Blue. Colourless. 360 D0. Pale yellow 226 Blue-violet. do 214215 Do.

N H do 354-356 Blue.

-CH= CH-N EXAMPLE 2 is obtained S-nitro-benzotriazole-(Z)-acetic acid in the 19 g. S-methyl-benzotriazole-(2)-acetic acid, 16.5 g. 4- acetylamino-benzaldehyde and 7 cc. piperidine are heated at l70l80 C. for minutes. In the course of the reaction, the waterformed is distilled off. The reaction mixture is poured on to ice-Water, the separated material is filtered 01f with suction and redissolved from a small amount of alcohol. There is obtained Z-p-acetyl-aminostyryl-S-methyl-benzotriazole of MP. 228.231 C. in the form of pale yellow crystals.

When dissolved in ethyl acetate or N,N'-dimethyl formamide, the compound has an intense blue fluorescence in daylight. The S-methyl-benzotriazole-(2)-acetic acid was obtained as follows: 167 g. S-methyl-benzotriazole, 158 g. sodium carbonate, 2 litres water and 132 g. chloro-acetic acid are heated for 5 hours under reflux and while stirring. After cooling, the reaction mixture is rendered acid to Congo and the separated reaction product is filtered form of small pale yellow crystals which melt at 208 211 C.

EXAMPLE 4 687 g. S-nitro-benzotriazole-(2)-acetic acid, 318 g. benzaldehyde and cc. piperidine are heated under reflux, while stirring, in 2 litres o-dichlorobenzene. '1'he water formed in the reaction is distilled 01f together with some o-dichlorobenzene. When Water no longer distills over, this being the case after about 5 hours, the reaction mixture is cooled and the separated yellow crystals are filtered olf with suction. Two thirds of the 1,2-dichlorobenzene are distilled off from the mother liquor, and the crystals precipitated from the distillation residue are also filtered 01? with suction. There are thus obtained 235 g. 5-nitro-2-styryl benzotriazole which melts at 168-171 C. after redissolution from glycolmonomethyl ether acetate.

We claim: 1. Process for the production of novel benzotriazole derivatives, characterized in that a benzotriazole-(2)- acetic acid of the general formula in which x stands for 1, 2 or 3, and R means hydrogen,

lower alkyl, lower alkoxy, acetylamino, di-lower-alkylamino, halogen, CN, COOH, SO H, or SO -l0wer alkyl is reacted with at least the stoichiometrically required amount of an optionally substituted benzaldehyde of the formula OHG in which y stands for 1, 2 or 3, and R may be identical with or difierent from R and where one of the radicals R may also denote an aldehyde group in the presence of piperidine, within a temperature range of about 120 to about 200 C., and the water formed in the reaction is continuously removed if desired.

2. A benzotriazole compound of the formula in which at and y stand for 1, 2 or 3, and wherein R is selected from the group consisting of hydrogen, lower alkyl, lower alkoxy, acetylamino, di-lower-alkylamino, halogen, CN, COOH, SO H, and -SO -lower alkyl, and wherein R may be identical with or different from R and may also denote, if y is equal to 1, the radical References Cited UNITED STATES PATENTS 2,784,184 3/ 1957 Zweidler et al. 260-240 3,101,333 8/1963 Adams et al. 260-240 FOREIGN PATENTS 874,456 5/ 1942 France.

OTHER REFERENCES JOHN D. RANDOLPH, Primary Examiner US. Cl. X.R. 

